Optical remote sensing makes use of visible (0.4 µm to 0.7 µm) and infrared (0.7 µm to 3.0 µm) wavelengths to form images of the Earth's surface by detecting the solar radiation reflected from targets on the ground. Different materials reflect and absorb differently at different wavelengths. Thus, the targets can be differentiated by their spectral reflectance signatures in the remotely sensed images. Optical remote sensing instruments are classified into the following types depending on the number of spectral bands/wavelengths used in the imaging process: panchromatic, multispectral, superspectral, and hyperspectral.

Classification of vegetation and land-use is a common use of optical remote sensing, and may be performed at a variety of temporal and spatial scales. For specific details regarding the optical remote sensing data at NSIDC, please refer to the instrument descriptions below.

MODIS: The MODIS instruments provide calibrated, geolocated radiance data from 36 spectral bands, and a series of geophysical products from land, ocean, and atmosphere disciplines that can be used for studies of processes and trends on local to global scales.

AVHRR: The AVHRR instrument provides measurements for a broad range of environmental factors including weather, clouds, snow, ice, and sea surface temperature.

TOVS: The TIROS Operational Vertical Sounder (TOVS) suite of instruments provides vital measurements for weather forecasting, supplying users with information on the vertical distribution of temperature and moisture in the global atmosphere. TOVS has been particularly useful in providing atmospheric soundings over regions where in situ measurements are sparse.